Motor vehicle injury and damage prevention system

ABSTRACT

A MOTOR VEHICLE DAMAGE AND INJURY PREVENTING SYSTEM IS DISCLOSED. THE SYSTEM IS BASED UPON SHOCK-ABSORBING BUMPERS EXTENDING OVER SUBSTANTIALLY THE ENTIRE FLATTENED FRONT AND REAR ENDS OF A SPECIALLY DESIGNED VEHICLE AND MADE UP OF A RELATIVELY THIN SHEET OF COMPRESSIBLE, RIGID BUT BENDABLE, SHOCK-ABSORBING, IMPACT-RESISTANT MATERIAL ON THE OUTER FACE OF WHICH IS A RELATIVELY THICK MASS OF CELLULAR SHOCK-ABSORBING PLASTIC MATERIAL. TYPICALLY A SECOND RELATIVELY THIN SHEET OF THE IMPACT-RESISTANT MATERIAL IS PROVIDED ON THE OUTER PORTION OF THE CELLULAR   SHOCK-ABSORBING PLASTIC MATERIAL AND A SECOND RELATIVELY THICK MASS OF THE CELLULAR SHOCK-ABSORBING PLASTIC MATERIAL IS PROVIDED ON THE OUTER PORTION OF THIS SECOND SHEET. IN THIS WAY THE SECOND SHEET CAN MOVE INWARDLY AND DISTRIBUTE THE FORCE OF IMPACTS DURING COLLISIONS OVER THE ENTIRE AREA OF THE CELLULAR PLASTIC BEHIND IT AND ALSO OVER THE ENTIRE FLATTENED END OF THE VEHICLE.

Nov. 14, 1872 A. s. BECKLEY 3,702,111

MOTOR VEHICLE INJURY AND DAMAGE PREVENTION SYSTEM Filed May 8, 1970 4 Sheets-Sheet 1' I N VENTUR. floo/saw '5. 560mm! BY 9 02.20%. W- ,qrmlewa'r 1972 A. s. BECKLEY 3,702," l

MOTOR VEHICLE INJURY AND DAMAGE PREVENTION SYSTEM Filed May 8, 1970 4 Sheets-Sheet z 1DJ-5l9 INVENTOR 400/30 5 550mg Nov. 14, 1972 A. s. BECKLEY 3,702,711

MOTOR VEHICLE INJURY AND DAMAGE PREVENTION SYSTEM Filed lay a, 1970 4 Sheets-Sheet 8 INVE.\'TOR. 400/80 5. fi'cKofy ibfyfliwm Nov. 14, 1072 MOTOR VEHICLE INJURY AND DAIIAGE PREVENTION SYSTEM Filed lay a, 1970 STIFFNESS (ET /l2) A. S. BECKLEY 4 Shoots-Shut A WEIGHT IN LBS. PER SQUARE FOOT INVENTOR flmsa v 6. Banner may United States Patent US. Cl. 296-31 P 26 Claims ABSTRACT OF THE DISCLOSURE A motor vehicle damage and injury preventing system is disclosed. The system is based upon shock-absorbing bumpers extending over substantially the entire flattened front and rear ends of a specially designed vehicle and made up of a relatively thin sheet of compressible, rigid but bendable, shock-absorbing, impact-resistant material on the outer face of which is a relatively thick mass of cellular shock-absorbing plastic material. Typically a second relatively thin sheet of the impact-resistant material is provided on the outer portion of the cellular shock-absorbing plastic material and a second relative ly thick mass of the cellular shock-absorbing plastic material is provided on the outer portion of this second sheet. In this way the second sheet can move inwardly and distribute the force of impacts during collisions over the entire area of the cellular plastic behind it and also over the entire flattened end of the vehicle.

The body of the motor vehicle is preferably made from relatively thin sheet-like compressible, rigid but bendable, shock-absorbing, impact-resistant plastic material of the same general type as that used as the rigid elements in the bumpers. Other novel features of the disclosure include special interior crash pads of cellular shockabsorbing plastic material placed in front of and close to the occupants and reaching to roughly the levels of their lower faces in such a way as not to interfere unduly with their freedom of action or reduce their range of vision, means for preventing undesired sagging of the cellular plastic shock-absorbing elements of the bumpers, means for restraining rocking and bending of the bumpers during certain types of collisions, and means for off-setting the high inertia of engine blocks and other heavy components during collisions.

BACKGROUND OF THE INVENTION (1) Field of the invention The invention pertains to a system which greatly reduces or prevents altogether the injuries and property damage and consequent suffering, deaths and expense incident to motor vehicle collisions. The invention accomplishes this result by providing the motor vehicle with novel means which cooperate to absorb the energy of impacts in such a way as to minimize the harmful etfects of collisions on the vehicle and its occupants and to minimize damage or injury to other vehicles, property, pedestrians, cyclists, animals, etc. struck by or in collisions with the vehicle constructed and equipped according to the invention. These results are achieved with minimum permanent distortion or other damage to the vehicle. Thus medical and repair bills and insurance costs are greatly reduced.

(2) Background of the invention Conventional metal automobile bumpers and bodies are totally inadequate from the standpoints of damage and safety because, with them, even at such low parking lot speeds as five to ten miles an hour the repair bills normally run to hundreds of dollars per collision while 3,702,711 Patented Nov. 14, 1972 many deaths and injuries and more than percent of property damage arise in accidents occurring at speeds not over thirty miles per hour. The severity of injuries and damage tends to increase geometrically with, i.e. with the square of, the speed of collision. The result is an astronomical burden of death, injury, suffering and property damage.

Prior art workers have endeavored in many ways to reduce the severity of the consequences of automobile accidents, but no truly effective solution deemed worthy of wide adoption, at reasonable costs, and not entailing serious disadvantages has heretofore been proposed.

During 1958, Cornell Aeronautical Laboratory, Inc. conducted tests (described in its unpublished Report No. YB-1004-D-5) for United States Rubber Company which indicated that for crash impacts up to approximately only 8 miles per hour the effectiveness of conventional metal automobile bumpers mounted on brackets extending away from the chassis could be enhanced by providing a metal back-up plate about six inches behind the bumper and filling the space between the bumper and the back-up plate with a lightweight energy-absorbing material known as No. 22266 Ensolite (trademark) manufactured by United States Rubber Company, together with supporting leaf springs. In the tests the car equipped with this narrow horizontal bumper was caused to collide with a vertical telephone pole. In this relatively infrequent type of accident, the shockabsorbing frontal area of the Ensolite was only about 360 square inches and in the collision only a fraction of this small area was brought vigorously into play. Consequently the Cornell tests had no impact whatever on the art and amounted to merely abandoned experiments.

Recently water bumpers have been used to a limited extent, particularly by taxi fleets. Such bumpers are described in Consumer Reports for September 1969, pages 514-515. While they can reduce vehicle damage at speeds up to 10 miles per hour, at higher speeds the bumper itself is usually damaged and at speeds of the order of 20-30 miles per hour extensive damage to the vehicle itself and passenger injury occur. Moreover, unless the heights of the narrow bumpers involved match one another, the water bumpers have little or no effect even at low speeds such as are encountered in parking collisions. Also they increase the vehicle length by about 12 inches, increase the vehicle weight by about pounds and have to be filled with water and antifreeze, which are sprayed into the air during collisions. Water bumpers do not begin to approach in effectiveness the safety system of the present invention which is highly effective in reducing injuries and damage at much higher speeds than those for which the water bumper is useful. The relative in effectiveness of Water bumpers is partly due to the fact that they are narrow and transmit the force of the collision to the chassis only, in line with conventional automobile bumper design. This is in contrast to the present invention in which the force of collisions is transmitted to the entire frontal or rear end area of the vehicle. For a water bumper to protect the entire front end of an automobile and provide sufficient stroke length for collisions at moderate driving speeds, it would have to weigh more than 500 pounds. Corresponding rear end protection would add at least 250 pounds to the weigh of the vehicle.

Another recent development which has resulted in reports of rather good crash test results at speeds up to 25-30 miles per hour has involved the use of metal bumpers backed by metal shock absorbers filled with compressible silicone rubber, mounted on conventional metal automobiles. However this proposal undoubtedly requires extra weight, extra overall vehicle length, and

high costs, fails to protect pedestrians, the fenders and bodies of other vehicles, or stationary objects hit by vehicles, fails to reduce the damage vulnerability of present metal bodies, fails to give adequately increased protection to vehicles or passengers in lateral collisions or roll-overs, and fails to distribute part of the collision forces directly to vehicle bodies and engines as well as to chassis, in contradistinction to the present invention.

A major automobile producer has recently indicated (Chemical Week for Nov. 5, 1969, page 21) that promising results are now being obtained with a rubberized bumper consisting of a porous rubber compound, evidently employing a tripolymer based on neoprene having high restorability characteristics, wrapped around a heavy gauge metal frame. However this falls far short of the present invention and would not be nearly as effective.

Another type of narrow bumper of conventional dimensions which has been recently developed is one based on a core or body of cellular polyurethane coated with a protective non-cellular skin of polymeric material. However, because of the inherent limitations of the design of this type of bumper, it gives only very limited protection to the vehicle and almost no protection to its occupants.

Infiatable air bags which are located in the passenger compartment and inflated instantaneously upon collision are now the subject of much experimentation. However, these do not protect the vehicle from damage and moreover are themselves subject to certain serious disadvantages such as limited reliability and the possibility of injury to individuals of weights and sizes or sitting positions different from those for which specific air bags were designed. Nevertheless, if and when inflatable air bags are perfected, they could be used in conjunction with major features of the present invention as alternate or complementary interior protection for occupants.

Interior seat belts have long been used in vehicles to reduce injuries to occupants. They have the advantage of decelerating the occupant simultaneously with the deceleration of the crashing vehicle. However, conventional vehicle decelerations during collisions are often erratic, exerting severe shocks, and the narrow belts can exert injuriously severe restraints on parts of occupants bodies during severe shocks. Moreover, occupants often fail to fasten their seat belts, rendering them useless.

Present interior crash pads of vehicles are generally made of relatively stiff material which can injure occupants. They are located too low relative to occupants bodies to prevent them from hurtling against or through Windshields. They are also too narrow to decelerate occupants without injury even in moderately severe collisions. Finally, they are located too far away from vehicle occupants, so that occupants generally strike these pads at nearly full collision speeds after the vehicles have already been brought to complete stops.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is a side elevation of a typical motor vehicle embodying a safety system of the present invention;

FIG. 2 is a plan view of the motor vehicle of FIG. 1;

FIG. 3 is a front elevation of the motor vehicle of FIGS. 1 and 2;

FIG. 4 is a detailed view, mainly in section, taken on the line 44 of FIG. 2;

FIG. 5 is a sectional view, taken on the line 55 of FIG. 1, of a preferred rigid laminated material (hereinafter laminate") used in the body of the motor vehicle of the present invention and in the bumpers of the vehicle as well;

FIG. 6 is a view looking forward toward the steering wheel and crash pads on the drive-rs side of the vehicle of FIGS. 1 to 3;

FIG. 7 is a sectional view taken on the line 7-7 of FIG. 6;

FIG. 8 is a plan view, taken on the line 8-8 of FIG. 7, of the interior crash pads, instrument panel and steering wheel; and

FIG. 9 is a graph which shows the stiffness of the preferred plastic laminate used in the invention, in comparison with other structural materials.

SUMMARY OF THE INVENTION The safety system of this invention delivers to the occupants G forces of deceleration or acceleration which are less than the limits of human tolerance, using bumper thicknesses much less than those which have been assumed to be required by physicists conversant with the problem. This result derives partly from the very short time intervals of deceleration or acceleration at the speeds, bumper thicknesses and crash pad thicknesses involved, making higher G levels tolerable. It also derives from the fact that the front interior crash pads are raised, made more extensive, made thick enough to allow adequate deceleration distances for vehicle occupants, and placed closer to vehicle occupants than are present conventional crash pads, so that the occupants can be decelerated over distances greater than the stroke lengths of the interior crash pads alone. Thirdly, it derived from redesigned vehicles utilizing bodies made of impact-resistant, shock-absorbing material and having essentially flat front and rear ends extending completely across the vehicle in both the horizontal and the vertical directions. The headlights and taillights are recessed longitudinally and conventional grill work, bumpers, bumper braces, decorative elements, etc. commonly provided on the front and rear of motor vehicles are completely eliminated, being replaced by safety bumpers which are mounted directly on both the chassis and bodies and which incorporate compressible cellular materials having unusually large frontal areas and therefore able to exert total decelerating or accelerating forces which are unusually large for such compressible materials. Fourthly, it derives from use in the bumpers and the interior crash pads of shock-absorbing padding materials which exert greater compression resistance during early stages of each impact compression than do other types of flexible foam, exert greater average compression resistance during high speed impacts than during low speed impacts, and exert low rebound energy relative to impact energy. These attributes make it possible for such materials to decelerate or accelerate vehicles colliding at relatively high speeds over an unusually short distance with unusually moderate G forces, and to exert more moderate G forces during lateral, back-to-front, and lower speed collisions, during collision impacts involving more than one mass of shock-absorbing material, and during bumper impacts with lightweight objects such as people and animals than are required for head-on vehicle collisions occurring at higher speeds.

Fifthly, it derives from a special sandwich-type bumper construction which enables the system to operate effectively in collisions from various angles, in off-center collisions, and in collisions with narrow objects such as trees, telephone poles, and narrow metal bumpers. Additional advantages derived from the materials and novel constructions used are described herein. The result is a great reduction in frequency and severity of damage and injuries arising from motor vehicle collisions.

As used herein the term "collision includes collisions with other vehicles and objects, pedestrians, cyclists, etc. In accordance with accepted principles of physics, the term G as used herein is the ratio F/ W or a/g where F equals the net force being exerted against any object, W is the weight of any such object, a is the acceleration or deceleration being experienced by any such object during a collision, and g is the acceleration due to gravity of a. falling body in the absence of any air resistance.

DETAILED DESCRIPTION OF THE INVENTION As use-d herein, the word laminate is used in a narrow sense to refer to a laminate of solid plastic cover layers which are bonded, preferably integrally, to an inner rigid cellular plastic core which typically and preferably is unicellular ABS (acrylonitrile-butadiene-styrene resinous material), this laminate having a stiffness in flexure (ET /12) at least as great as that shown by the curve labelled Laminate in FIG. 9 of the accompanying drawings, which shows the stiffness of the laminate at various weights per square foot in comparison with the stilfnesses of other materials commonly used for vehicles bodies. (E is the fiexural modulus and T is the total thickness of the laminate.) The laminate has an impact resistance such that it is capable of withstanding without breaking the impact of a 2 lb. steel ball dropped on it from heights up to 9 feet at temperatures ranging from minus 40 F. to 175 F. The ET /l2 relationship is a measurement of rigidity and is a measured unit. This kind of laminate is described in detail on pages 344-352 of Rigid Plastics Foams," Second Edition, 1967 published by Reinhold, by T. H. Serrigno. It is also described in a recent brochure entitled Royalex ABS: properties and uses published by Uniroyal, Inc. and in an earlier brochure entitled The Indestructible Cord published by United States Rubber Company. Methods of manufacturing such a laminate are detailed in US. Patents 3,041,220; 3,070,- 817; 3,206,354; 3,356,560; 3,386,878; and 3,463,687. Without intending to be limiting, it may be stated that the thickness of such laminates typically ranges from 0.25 to 0.75 inch, the density typically ranges from to 35 pounds per cubic foot, the tensile strength is at least 1500 p.s.i., the heat distortion temperature at 250 p.s.i. is at least 180 F., the compressive strength is at least 200 p.s.i., the stiffness referred to above increases by less than 10% as the temperature is reduced from room temperature to 0 F. and decreases by less than 50% when the temperature is raised from room temperature to 180 F. and that the core of the laminate usually constitutes most, say 70% to 80%, of the total thickness of the laminate. As described later, such laminates also have other properties advantageous in reducing injury and damage.

As used in this description, the term padding means a unicellular shock-absorbing plastic material having the following physical properties:

DensityNot over 35 lbs. per cu. ft.

% compression resistance (dynamic at approximately 25 miles per hour, for 12-inch padding thickness)- At least 15 lbs. per sq. in.

Tensile strength-At least 15 lbs. per sq. in.

Maximum water absorption (cut surface)Not over 1 lb. per sq. ft.

Rebound energy delivered-Not more than of impact energy 1 Preferably at least lbs. per sq. in. for the padding used In the bumpers.

At the present time, the preferred forms of such material are the shock-absorbing types of unicellular (closed cell) plastic foam sold under the trademark Ensolite" by Uniroyal, Inc. and described in the Uniroyal brochures Ensolite Safety Material (1967) and Ensolite (1969).

These Ensolite materials are chemically blown or foamed blends of thermoplastic resin such as polyvinyl chloride alone or with a small amount of ABS, butadieneacrylonitrile rubber (NBR) and one or more compatible plasticizers in proportions of from 10% to 70% (preferably 45% to of said resin, for 16% to 80% (preferably 30% to 45%) of said rubber, and from 6% to 60% (preferably 6% to 12%) of said plasticizer(s), said percentages being by weight based on the sum of said constituents and totalling 100%, and are made in the manner taught in US. Patents 2,570,182

and 2,757,147. Particularly preferred are Ensolite types AA, AH, AL and LDAF. The physical properties of types AA, AH and AL are shown in the brochures just cited while those of type LDAF are shown in Uniroyal Technical Data Bulletin entitled Ensolite & Kem-Blo dated March 1969, However, the invention is not limited to the use of Ensolite foam but can be practiced with equivalent compressible, unicellular foamed plastic materials such as those based primarily on polyurethanes, vinyl polymers, polyethylene, polypropylene, or polystyrene, such rubbers as neoprene, Buna N, SBR, and blends of such polymers with one another or with other compatible polymers such as for example ABS, etc.

Referring now to the accompanying drawings, FIGS. 1 through 8 portray an automobile incorporating a typical safety system of the present invention comprising the following three principal elements which are detailed below:

(1) Laminate-padding bumpers both front and rear. (2) Laminate body including fenders, and (3) Specially designed interior crash pads.

(l) The bumpers The automobile body 1 has flattened front and rear ends upon which are mounted front and rear bumpers 2 and 3. Fixed vertical sheets 4 and 5 of laminate (double sheets can be used if desired) are fastened in any suitable way across the front and back contiguous with both the body 1 and the chassis 6 so that they are braced by the body and chassis and so that impact forces reaching sheets 4 and 5 are transferred directly and simultaneously to the body and chassis. Typically the body is made from the laminate and the chassis made of metal. The front and rear metal channel cross members 7 of the chassis 6 can be extended laterally substantially entirely across the width of the vehicle so as to brace the extremities of the bumpers and to help restrain the front and rear wheel assemblies during severe collisions. In such case, a smooth, strong covering element 8, which can be made of metal, is provided across the ends of channel members 7 to prevent injury to tires and wheels when they are pressed against extended channel members 7 during severe collisions.

Laminate sheets 4 and 5 extend across the entire width and the entire front and rear heights of the vehicle except for the corner areas where the headlights and the taillights are located. Typically these sheets measure at least two feet up and down.

The design of the vehicle is such that both the front and the rear wheel assemblies 9 are moved further back than in a typical conventional vehicle. The front wheel assembly is moved back in order to allow the front bumper 2 to extend completely across the front of the vehicle and to restrain and protect the front wheel assembly during deceleration in a severe front-end collision. The rear wheel assembly is moved back to avoid an excessively short wheel base and also to locate this assembly sufficiently close to the rear bumper 3 that the rear wheel assembly is restrained and protected during acceleration due to a severe rear-end collision.

A relatively thick (compared to the laminate sheet 4) layer 11 (typically 8 inches thick) of padding is cemented or otherwise securely mounted in front of laminate 4 in the front bumper 2. A corresponding relatively thick layer 12 (typically 4 inches thick) of padding is likewise secured on the face of laminate sheet 5 in the rear bumper 3. These padding masses 11 and 12 are typically made by plying-up relatively thin sheets of padding as by cementing; the reason for this is that most of these padding materials are now commercially available at reasonable cost only in thicknesses not greater than 1 or 2 inches.

Padding layers 11 and 12 have substantially the same area profiles as laminate sheets 4 and 5. As shown, they are tapered slightly for better road visibility and appearance and for better headlight and taillight clearance.

A floating, vertical sheet of laminate (or two sheets thereof if desired) 13 is sandwiched, as by cementing, between the inner padding mass 11 and an outer padding mass 14 on the front bumper 2. Likewise a floating vertical sheet of laminate 15 is sandwiched between inner padding mass 12 and an outer padding mass 16 on the rear bumper 3. These floating laminate sheets 13 and 15 are made slightly narrower, say 1 inch less at each side, than the width of the padding masses between which they are sandwiched, the resulting slots being filled with rims of padding to reduce the force of impact against the floating sheets in lateral collisions; this treatment also helps to prevent snagging of the floating sheets 13 and 15 against other vehicles during parking and reduces wear on the straps described later. It is preferable to cement such rims of padding only to the edges of the floating laminate sheets and to the outer layers of padding but not to the inner layers of padding; the reason for this is to avoid unnecessary stretching, tearing or delamination during off-center collisions or collisions with narrow objects, which could force momentary separation at the outer extremities.

The front layer 14 of padding is mounted, as by cementing, on the outer face of the floating laminate sheet 13. This layer 14 typically is 4 inches thick. Likewise the outer layer 16 of padding, typically 2 inches thick, is secured on the outer face of laminate sheet 15 in the rear bumper. These outer layers of padding 14 and 16 have approximately the same measurements across the vehicle and vertically as the padding masses 11 and 12, respectively, but are preferably tapered slightly and rounded off for better road visibility and appearance and clearance for headlights and taillights.

All of the padding material in the bumpers is preferably coated on its outside with polyvinyl chloride or other suitable material for better appearance, weather protection, abrasion resistance, durability and slipperiness. Any such coating can be pigmented to match the color of the vehicle body 1.

The floating laminate sheet should be located as far out from the fixed sheet as is possible without causing the floating sheet to be broken by typically narrow objects encountered in collisions, such as conventional metal bumpers and telephone poles, at the maximum collision speed which the vehicle is designed to handle without damage or injury to occupants, in order to spread out the forces of impact to as thick an inner layer of padding as possible. Often the floating laminate sheet is so located that the outer padding layer is one-fourth to three-fourths as thick as the inner padding layer.

Two laterally spaced inextensible connecting elements 17 are shown as being provided in the right-hand and lefthand portions of the front bumper 2. If desired, similarly located inextensible elements (not shown) can be provided in the rear bumper 3. These elements can conveniently take the form of metal chains, as shown in the drawings, or equivalent means such as inextensible straps, ropes or cables. Elements 17 are shown as being fixedly attached to the lower portion of the floating laminate sheet 13 and as fixedly but adjusta'bly attached to the upper portion of the inner laminate sheet 4. lnextensible elements 17 prevent sagging, with the passage of time, of the inner padding mass 11. The effective lengths of elements 17 can be adjusted in any suitable manner; for example, with the chains shown in the drawings this adjustment can be made by means of padlocks 18 in the obvious manner. Such padlocks or other attachments at the upper ends of elements 17, or the upper ends of elements 17 themselves, preferably are made weaker than the rest of elements 17 and their connections with floating sheets 13 and 15, in order to avoid any breakage in hard-to-reach interior parts of the bumper.

It is preferred to provide each of the bumpers with inextensible means for preventing significant longitudinal movement of the outer extremities of the floating laminate sheets 13 and 15 away from the fixed laminate sheets 4 and 5, respectively, during off-center collisions or collisions with narrow objects, but permitting the floating laminate sheets to move freely toward the fixed laminate sheets during collisions. One way of achieving this which is portrayed in the drawings involves the provision of non-stretchable straps 20 wrapped around the exposed portions of both front and rear bumpers both horizontally and vertically. As shown, the front bumper is provided with four such straps wrapped around it front to back vertically and two such straps wrapped around it front to back horizontally, thus crossing the four vertical straps. The rear bumper is provided with two such straps wrapped vertically and two wrapped horizontally. As will be obvious, these straps can be equipped with any suitable means, such as metal buckles, or stops, to adjust their lengths. Any suitable means can be provided to prevent loss or dislocation of the straps during collisions. The outside surfaces of the straps should be made slippery in any suitable way as by coating, in order to promote sliding during off-center collisions. These straps can match the vehicle in color or can be in contrasting racing stripe colors for greater visibility and safety. In any case the straps should be white or bright colored in front of the headlights and in back of the taillights for lateral visibility at night.

An alternative to the encircling straps shown in the drawings would consist of inextensible straps, ropes, cables or chains attached longitudinally between the two laminate sheets in each bumper at positions near their extremities, so that the edges of the movable laminate sheet would be restrained from moving away from the fixed laminate sheet during off-center or narrow-object collisions.

Still another alternative would be to enclose part or all of the exposed portions of each bumper in a jacket or sleeve of flexible inextensible sheet material, such as square woven fabric having a suitable plastic coating for appearance, durability, slipperiness and weather protection, secured in any suitable manner to the fixed laminate sheet.

The mechanical purposes of the encircling straps shown in the drawings and the alternatives thereto which have just been described are (1) to help prevent bumper sagging, (2) to help hold the bumper together in case of rear quarter collisions against the front bumper alone, such as often occur during parking, (3) to spread further the initial impacts of narrow objects, such as metal bumpers and trees, by converting part of such impacts into compressions of the outer surfaces and edges of the safety bumpers, and (4) to keep the outer ends, tops and bottoms of the floating laminate sheets and the layers of padding from rocking or bending excessively during elf-center collisions or collisions with narrow objects such as trees or bumpers. This fourth function helps prevent ply separation, reinforces the floating laminate sheet and the layers of padding during narrow-object collisions, and increases the effective shock-absorbing area of the mass of padding sandwiched between the floating and the fixed laminate sheets during off-center and narrowobject collisions.

To assist in deceleration or acceleration of the engine or other heavy internal components of the vehicle such as the differential assembly, laterally spaced fixed metal braces, extending generally longitudinally, are provided where desired between the fixed laminate sheets of the bumpers and such heavy internal components of the vehicle. These are exemplified by metal braces 21 fastened in any suitable manner with broad metal bases to the fixed vertical laminate sheet 4 of the front bumper 2 and extending directly to the engine 22. In addition, the conventional moorings of engines and other heavy components preferably are reinforced in any suitable way to further reduce the possibility or extent of damage.

Certain optional features which can be used to improve the efficiency, utility, or marketability of the bumpers include:

(1) License plates made from soft, flexible EPDM rubber which avoids damage and injuries and resists fading and cracking on prolonged exposure to weather,

(2) White paint, coating or other light coloration on the vertical upper sides of the bumpers and on the straps located in front of the headlights or in back of the taillights to make them visible from the sides at night,

(3) Decks of cheap, disposable, plastic film slip covers extending across the front and around the sides of at least the lower portions (below headlights and taillights) of the bumpers, the purpose of these being to slip off one at a time to promote sliding and reduce the possibility of tearing up the padding during off-center collisions.

During most collisions, the up and down width, typically about two feet, and the lengths (typically equal to the width of the vehicle) of the front and rear bumpers insure that at least one safety bumper will intervene between each vehicle and the object causing the impact. The over-under jumping of conventional narrow metal bumpers of different heights is avoided. An unusually large safety bumper area, typically more than 1,400 square inches, is available at each end of the vehicle to resist impacts with approximately flat surfaces, enabling the padding to resist large total impact forces with only relatively moderate compression resistance in terms of pounds per square inch of frontal area. The outer layer of padding, because of its large frontal area, its compression resistance, and its tensile strength, reduces the force of impact with both wide and narrow objects by offering resistance While being compressed through up to 75 percent or more of its initial thickness. Thus it reduces damage to these colliding objects. It also cushions the impact of living people pedestrians or cyclists) and animals striking the front or back of the vehicle, saving them in many cases from death or injury. As a crash progresses, this outer layer of padding prolongs and reduces the force of impact acting against the floating rigid vertical sheet of laminate 13 or 15, pushing this sheet inward with a controlled build-up of force and reducing the possibility of damage to the colliding object, and, if the colliding object is another car, to its occupants In addition, the outer layer of padding on the bumpers offers increasingly higher compression resistance per square inch to narrow objects such as trees and metal bumpers and also increasingly spreads out the area of their force of impact against the floating sheets of laminate as the collision progresses. These effects arise from the tensile strength of the padding and the related diagonal compression resistance of the padding compressed beneath the padding which is stretched around the narrow area of impact. All three effects help keep the floating laminate sheet from being broken by violent collisions with narrow objects.

The floating laminate sheets 13 or 15, in turn, may bend or compress slightly as the crash progresses, further reducing the forces of impact. However, the laminate has great resistance to sharp bending and to impacts, and it is reinforced and stabilized by restraining forces exerted by the inextensible restraining means typified by straps or alternatives thereto such as are described above. Thus the floating laminate sheet remains relatively flat during collisions with narrow objects, and rocks only slightly or not at all during off-center collisions. As a result, it spreads the force of impact over substantially the entire area of the thick inner layer of paddings 11 or 12, enabling this inner padding layer to resist large impact forces from both wide and narrow objects and from both on-center and off-center collisions. This inner layer of padding, which can also compress by 75% or more, further prolongs and reduces the remaining force of impact of the collision, further spreads the force out, and transfers it as a spread-out, reduced force of longer duration to the fixed laminate sheet 4 or 5 disposed across the front or rear of the vehicle body and chassis. This fixed laminate sheet, in turn, flexes and compresses slightly under heavy pressures, further moderating the impact force and transferring the moderated impact force directly and simultaneously to the body and chassis of the vehicle, and by means of metal braces, such as those indicated by reference numeral 21, directly and simultaneously to the engine or other heavy internal components of the vehicle protected by such braces, greatly reducing stresses on the connections between the various parts of the vehicle. All these further reductions of the forces of impact also further reduce damage to colliding objects.

A final prolongation and moderation of heavy impact forces is achieved in the preferred embodiment of the invention wherein the body 1 of the vehicle is formed from laminate. With this construction, part of the impact forces are transmitted from the fixed vertical laminate sheets 4 and 5 of the bumpers 2 and 3 to the body 1 of the vehicle which compresses longitudinally.

In case of a collision so violent as to overwhelm all of the foregoing moderating barriers, the padding material, the movable and the fixed vertical laminate sheets, and the laminate vehicle body can bend, compress, dent, and crush beyond their recovery limits, further prolong.- ing and moderating the impact, without shattering, splintering, or collapsing.

Both the materialsv of the padding and the laminate tend to recover their shapes relatively slowly after deformations which do not exceed the recovery limits of these materials. This adds the advantage of minimizing vehicle bouncing during collisions. In case of off-center collisions, the padding (bringing into play its tensile strength and related diagonal compression resistance at the inside edge of the area of impact) and the floating laminate sheet (which is pressed toward the vehicle on one side harder than on the other) both tend to tilt toward the side of the collision. This tends to convert head-on collisions into sliding collisions wh1ch fend colliding vehicles away from each other and reduce the forces of impact, as when a ski-jumper lands safely from a great height onto the inclined plane of a ski jump, whereas a similar landing on a horizontal surface Would kill him. To accentuate this effect, the exposed surfaces of the bumper should be as slippery as possible. The desired slipperiness can be achieved by the use of very slippery coatings for the exposed surfaces of the padding and for any other exposed parts of the bumper such as the encircling straps 20, and/or by the use of the plastic film slip covers described above.

An additional function of the floating rigid sheet of laminate is to help prevent the padding from sagging after long periods of use. The individual layers of padding are attached to one another, as by cementing, and the resulting shock absorbing masses of padding are also attached, as by cementing, to both sides of the floating sheet of laminate which in the case of the front bumper is shown as in turn supported by the diagonally hung antisag elements 17.

The area of the bumpers of the present invention preferably is equal to at least 50% of the maximum crosssectional area of the vehicle including windshield and roof. With bumper areas less than 50%, the thickness of the bumper needed to absorb the impact of collisions occurring at driving speeds above 10-15 miles per hour has to be undesirably increased in order to achieve a bumper compression stroke length suflicient to offset the reduced compression-resisting area, and this either undesirably increases the overall length of the vehicle or undesirably reduces the usable space inside the vehicle or both.

The total thickness of the padding layers in the front bumper is typically and preferably at least 12 inches since this thickness would provide a stroke length of at least 9 inches, requiring no more than 72 Gs of average stopping force during the deceleration of a vehicle colliding at approximately 40 miles per hour. Lesser thicknesses generate Gs which would generally damage vehicles and seriously injure people. Greater thicknesses, up to about 18 inches for typical passenger cars, can be used to give equivalent protection at higher collision speeds or with very heavy vehicles or to reduce G at lower collision speeds but for typical passenger cars thicknesses greater than 18 inches would be inconvenient and generally unnecessary.

Similar considerations dictate the total thickness of the padding layers in the rear bumper except that this thickness should be approximately half that of the front bumper on a given vehicle, typically and preferably from 6 to 9 inches, to give approximately the same protection. The rear bumpers have only about half the thickness of the front bumpers for the following reasons:

(a) A front-to-back collision against a stationary vehicle requires only about one-half of the energy absorption by safety bumpers required in a head-on collision or in a crash against a fixed solid object at the same speed. A vehicle equipped with a half-thickness rear safety bumper of the invention can be struck from behind by a vehicle with no safety bumper at nearly the same damage-free or injury-free speed as would be tolerable for two vehicles equipped with full-thickness front safety bumpers colliding head-on.

(b) Vehicles backing up generally do not proceed as fast as vehicles moving forward.

(c) When most motor vehicles are made in accordance with the invention, back safety bumpers of the invention struck by front safety bumpers of the invention will pro vide combined shock-absorbing capability three times that provided when a half-thickness back safety bumper is struck by a vehicle with no safety bumper.

The total longitudinal space needed for the front and rear safety bumpers of the invention, typically from 19 to 28 inches, is offset by elimination of conventional bumpers, bumper guards, bumper braces, grill work, and heavy end structures of the chassis, so that the overall lengths of the vehicles of the invention are unchanged, and internal space loss is small. Also additional interior space is gained by building the car body with the upsloping hood described below and by positioning interior crash pads nearer to the front seat occupants, also as described below.

(2) The body As indicated in the drawings, the body 1 is constructed with flattened front and rear ends provided with the novel bumpers described above. The body, including the fenders, is constructed from the laminate a form of which is portrayed in FIG. 5. The innermost laminate sheets 4 and 5 of the front and rear bumpers actually constitute the front and rear ends of the body, being fixedly, and typically integrally, attached to the rest of the body in any suitable manner. If desired, the body 1 can be reinforced with steel members, such as roll bars, in certain areas for additional strength and to prevent buckling.

As indicated in FIG. 5, the laminate typically comprises a cellular core 23 on each side of which are solid substrate layers 24 and outer surface skin plies 25, all of these laminae being integrally bonded to one another in manufacture.

The laminate body and fenders can be easily formed, as by vacuum-forming, from the commercially available sheet laminate, using Well-known techniques of forming and of joining the various parts into an integral structure. Making the body and fenders from the laminate serves the following purposes:

(a) Reduce vehicle weight greatly, reducing necessary braking distances, frequency of accidents, average col- 12 lision speeds, and forces of impacts, as well as gasoline consumption.

(b) Absorb a substantial part of collision impact forces directly into the body from the fixed vertical laminate sheets 4 and 5, simplifying bumper construction and reducing stress on the chassis and on the connections between the chassis and the body. A metal body of reasonable weight could not perform these functions to a comparable degree without crumpling or bending permanently.

(c) Make bodies and fenders virtually undentable. Dents which do occur can be easily and cheaply repaired with heat guns, soap and water, and in extreme cases, with epoxy resins patches.

(d) Upon extreme impact during lateral collisions or capsizing accidents, bodies and fenders made from the laminate bend, compress, dent and ultimately crush without shattering, smashing, or collapsing. Thus they reduce the forces of impact to the vehicle frame and to the connections between frame, body, engine, etc., give the occupants better protection against collision shock and against vehicle body collapse, reduce bouncing, and produce no flying fragments, sharp edges, or splinters.

(e) In the most extreme head-on collisions, the laminate body can compress, dent, and ultimately crush longitudinally, further reducing impact forces and protecting occupants.

A special feature of the invention resides in providing an upwardly and rearwardly slanting hood 26 which slopes upwardly from the top of the fixed laminate sheet 4 to the windshield 27 at such an angle that its line of slope if extended would reach to a level approximating that of the lower facial areas of average-sized adult front seat occupants. This feature makes space which is now wasted available in the passenger compartment for accommodating the specially designed and arranged interior crash pads described below.

(3) The interior crash pads The interior crash pads consist primarily of top and bottom masses of padding 30 and 31 extending completely across the front portion of the passenger compartment. The longitudinal thickness of these crash pads preferably is 12 inches or more to ensure delivery of tolerable G forces to vehicle occupants. The pad 30 is located generally below and rearwardly of the windshield 27 with the upper surface of the pad at least as high as the rearmost portion of the sloping front hood and preferably with the upper surface of the pad in line with the slope of the front hood so that the upper rear rounded edge of the pad is roughly at the level of the lower facial portions of average-sized front seat occupants and its bottom portion at lower-chest or upper-stomach level. Pad 30 is also located further back and nearer to the front seat occupants than is the case now with conventional crash pads in conventional vehicles. This arrangement does not reduce the range of vision of occupants or interfere unduly with their freedom of action.

Pad 31 is located below and forward of pad 30. The two pads are so shaped and placed that during a crash the average occupants face, chest, shoulders, abdomen, knees and shins all plunge forward into the two crash pads simultaneously. Thus the occupants are not thrown against or through the windshield and are restrained and decelerated by relatively moderate pressure over most of the fronts of their bodies instead of the much higher pressures generated over a small portion of their bodies by narrow seat belts. This enables the occupants to tolerate far more than the 30 GS of stopping force known to be tolerable with seat belts. These advantages can be further accentuated by positioning pads 30 and 31 at distances from the front seat occupant less than the stopping distance of the vehicle during a collision in which the materials in the front bumper are fully compressed. In this way during severe collisions when the occupants are carried forward by inertia at nearly the speed of the vehicle at the start of impact, they strike the crash pads 30 and 31 of the decelerating vehicle before the vehicle completely stops, thus giving the occupants a total decelerating distance equal to the compression stroke of the interior crash pads plus the remaining distance traveled by the vehicle after the occupants strike the crash pads.

There is ample foot room between the lower crash pad 31 and the floor. A connecting mass 32 of padding is located between the lower portion of pad 30 and the upper portion of pad 31. Body elements 33, which can be made of laminate or of any other suitable material, are provided for the purpose of backing up the several pads as shown in FIG. 7. The extra space created by the sloping hood and by moving the crash pads back nearer to the front seat occupants can be used for instrument wiring, steering column, radio, etc. on the drivers side and as a storage compartment 34 extending from a partition 35 (shown in dotted lines) to vehicle body wall 36 on the passenger side, as shown in FIG. 8. For access to storage space 34, two or three segments 37 (FIGS. 2 and 8) of the top crash pad 30 are backed with laminate sheets which are attached by hinges to vertical body element 33 so that these segments can be swung upwardly to uncover a large access opening in element 33.

Instruments 40 on the drivers side are recessed and float in a recessed portion 41 of the crash pad 30. This recessed portion provides room for the driver to operate the steering wheel 42 which is preferably collapsible. On the steering wheel 42 is mounted a helmet-shaped mass 43 of padding which rotates with the steering wheel except during impact when it is momentarily crushed, along with the steering wheel, into portion 41 of pad 30, giving the driver a deceleration distance which includes the combined compressions of masses 41 and 43. If desired the foreand-aft thickness of the helmet-shaped padding mass 43 can be considerably reduced for greater convenience in operating the steering wheel but with corresponding sacrifice of shock-absorbing capability.

For additional reduction of impact forces transmitted to vehicle occupants, stretchable elastic seat belts can be used instead of the present conventional non-stretchable belts. The present conventional unstretchable seat belts, if duly fastened at the time of a collision occurring at the higher range of collision speeds which can be made tolerable by the invention, would exert unnecessarily heavy G forces on the vehicle occupants and severe pressures over relatively small portions of their bodies, and would not permit utilization of the interior crash pads provided in the invention to help decelerate the occupants. By contrast, the stretchable seat belts, if fastened, exert gentler pressures on the occupants, and their stretching allows the occupants to be further decelerated by the crash pads of the invention during severe collisions.

A child standing or kneeling on the front seat and leaning against the upper crash pad 30, a child or an adult whose safety belt is not fastened and who is thrown against the crash pad assembly by braking just before a collision, or any person who in anticipation of a frontal collision leans forward against the pad would be gradually decelerated over the total distance of the entire compression strokes of the front bumper, the laminate body and the interior crash pad, greatly reducing G forces exerted on such a person during the collision.

Desirably, padding is provided on the backs of the front seats, on the inside faces of the side walls of the vehicle, on door posts, etc. of the vehicle, for protection of rear seat occupants and for protection of all occupants during lateral collisions. The G forces generated by the bumpers of the safety vehicles in lateral collisions and in back-to-front collisions are generally less than the G forces generated during a head-on collision against a hard immovable object or with a vehicle of the same weight moving in the opposite direction at any given rate of collision speed, and vehicle velocity changes tend to be only half as great. Also, because of the low-rebound characteristics of the preferred materials in the vehicle bumpers and bodies of the invention, changes in velocities of vehicles in lateral or back-to-front collisions approach being only half as great as the initial speed of impact. Therefore the thickness of the interior padding just mentioned can be approximately one-fourth of the thickness of the masses of padding constituting front interior crash pads 30 and 31, generally without risking higher G forces being delivered to occupants in lateral collisions.

The thickness of upholstery foam now being used in the vertical portions of conventional vehicle seats, being compressed by the inertia of the occupants simultaneously with the relatively moderate acceleration of the vehicle hit during a back-to-front collision, gives the vehicle occupants less than half the G forces delivered in head-on collisions at the same speed.

Sample calculations of maximum damage-free, injuryfree collision speeds attainable, average G forces required at such speeds, and time intervals (t) of decelerations based on 75% compression of the padding 11 and 14 in the front safety bumper 2 or the front crash pads 30 and 31 alone, disregarding any further compression of the padding, any compression, bending, denting or crushof the laminates in the bumper and the body, or any simultaneous compression of interior crash padding while the vehicle is decelerating, are shown below.

Also shown below is a table of results from impact testing of samples of two commercially available types (Ensolite" AA and LDAF) of the preferred padding material at various impact speeds. The impact test equipment used to determine the compression resistance and the energy absorption of the cellular shock-absorbing materials tested for suitability for use in the safety bumpers and in the interior crash pads and the Gs generated during impact consisted essentially of a cylindrical impact head of greater diameter than the cylindrical samples of cellular material tested, a horizontal pneumatic cylinder to accelerate this impact head and associated inertial system to a desired horizontal velocity, a rigid vertical back plate to support a cylindrical test sample disposed with its axis horizontal and coaxial with the impact head, means for admitting compressed air to the cylinder to drive the impact head toward the sample, means for venting the pneumatic cylinder at a suitable point before the impact head reaches the sample thereby permitting the impact head and inertial system to coast freely into contact with the test sample, and instrumentation for measuring and recording the acceleration and position of the impact head as functions of time during impact. Impact velocity data are obtained from the slopepf the position record. The impact energy is calculated from the weight and impact velocity of the inertial system. Gs and dynamic compression resistances are calculated from the acceleration measurements. Rebound energy retransmitted to the impact head and inertial system is calculated from the velocity of the impact head measured at the point when the rebound acceleration drops to zero.

The impact head and associated inertial system weighed 17 pounds. The thickness (longitudinal) of the samples tested was approximately three inches. The diameter of the samples tested for safety bumper application was approximately 1.64 inches, and the diameter of the samples tested for interior padding application was approximately 2.69 inches. These dimensions were selected in order to facilitate calculation, by means of scaling formulas, of the G levels and impact time intervals which would occur during head-on collisions at typical highway speeds involving twelve-inch-thick safety bumpers and twelve-inch-thick interior padding, vehicle weights of approximately 2 pounds per square inch of bumper frontal area, and human body weights of approximately 0.75 pound per square inch of contact area between the interior padding and the human body. However, since the longitudinal thickness of the padding samples exceeded their diameters, since there was no penetration of the crash pad samples tested, and since some small movement of the back plate occurred during impacts, the test impacts encountered somewhat less than the full compression resistances the materials would exert in highway collisions. Also rebound energy measurements reached higher percentages of impact energy than are generally measured when steel ball bearings are dropped on the material.

These theoretical calculations and test results are also conservative because they are based on the pessimistic assumption that the vehicle equipped with the front safety bumper and front interior crash pads of the invention is either striking a hard, immovable object or colliding head-on with another vehicle of similar weight and equipped with a similar safety bumper and moving at the same speed but in the opposite direction. Collisions with soft or movable stationary objects including stationary vehicles would be damage-free and injury-free at higher crash speeds than indicated by these calculations and tests.

Sample theoretical calculations for head-on collisions.-

frontal area would be 2 lbs. per square inch. A similar ratio would apply for larger or smaller vehicles. Then:

(1) Deceleration of 80 Ge would require bumper padding compression resistance of F=ma=XGg=2X80= 160 lbs. per square inch (2) Deceleration of 40 Gs would require bumper padding compression resistance of 2x40=80 lbs. per square inch.

(i) Deceleration or acceleration of 80 Gs would require padding compression resistance of 60 lbs. per square inch.

(2) Deceleration or acceleration of 40 Gs would require padding compression of 30 lbs. per square inch.

RESULTS FROM IMPACT TESTING OF SAMPLES [Compression data includes some small movement of back plate] Percent max. Highway Rebound com- Max. decollision Highway Duration energy Number Dlam- Initial pression celeration velocity max. s of impact percent to Type of of previous star of thickduring Impact rate, eqnivaequivalent, eompresimpact Ensolite impacts sample, ness, lmpact, velocity, peak G's lent, peak G's sion (t), energy, in sample sustained inches inches percent it./sec. (Gs) m.p.h. (G's) sec. percent AA 0 1.650 3. 340 54 5. 84 3 16 12 061 15 AA. 1 1. 656 3. 272 70 8. 70 12 24 48 045 16 es... is: a a as 22 n 8 l8 8 ifg f gi 12 LDAF 1 1. 51s a. 03s 57 9. 10 12 2s 4a .032 u p LDAF 2 1. 578 2. 878 75 12. 53 22 34 88 029 13 LDAF 3 1.578 2. 735 83 16. 84 86 46 344 .028 12 LDAF 0 l. 687 3. 270 44 7. 76 14 21 66 081 7 LDAF 0 1. 672 3. 238 72 12. 13 24 33 96 032 11 iii a as: a 2 33 '35.? Tests scaled to 12 1 15 56 18 AA 1 2. 6156 3. 412 51 8. 0B 20 22 8D 036 20 AA 2 2. use a. 390 as 12.13 34 as 136 .032 2a A 3 2. 656 3. 367 76 16. 25 64 42 256 028 31 l Percent to original thickness before first impact.

Assuming maximum average deceleration 80 G's (a/g=80):

(1) Safety bumper thickness 12 inches, normal compression stroke 9' inches:

V =2aS=2 80gs=2 80X 32.2 X% =3,860

V: 62 ft. /sec.=42 m.p.h. maximum tolerable collision speed V 62 t= =.024 second duration of impact;

(2) Safety bumper thickness 18 inches, normal compression stroke 13.5 inches:

V=76 ft./sec.=52 m.p.h. maximum tolerable collision speed Assuming maximum average deceleration G's (a/g=40):

(1) Safety bumper 12 inches thick (9 inch stroke) could stop collision at 30 m.p.h. in .034 second.

( 2) Safety bumper 18 inches thick (13.5 inch stroke) could stop collision at 37 mph in .042 second.

As will be seen from the foregoing theoretical calculations, average G forces of are sufficient to stop vehicles in head-on collisions occurring at 42 miles per hour with l2-inch-thick padding and occurring at 52 miles per hour with l8-inch-thick padding. As will be seen from the foregoing test results, already available padding materials, if they were used in bumpers and crash pads only 12 inches thick, would keep peak Gs from greatly exceeding 80 at highway collision speeds up to about 30 mph. Padding materials selected, moditied, and used in the best combinations after even more extensive testing can be expected to further improve the good collision performances indicated by the foregoing test results. The time intervals during which average GS of 80 or higher are exerted will be less than 0.025 second with 12-inch-thick padding and less than 0.03 second with 18-inch-thick padding, and any peak G's exceeding 80 will last for much shorter time periods. Similar G forces would be exerted for similar time periods on a vehicle occupant striking the front crash pads of the invention at the same full head-on collision speeds after the vehicle had completely stopped.

A great amount of data based on volutary human experiments and accidental collisions, falls and other impacts involving humans, as assembled by NASA and others, indicates that Gs below 80 for time intervals below 0.03 second exerted at the angles and positions of people sitting in motor vehicles during head-on collisions are generally survivable. During collisions at various other angles, the front safety bumpers generally exert lower G levels, shorter time intervals of deceleration and acceleration, and smaller changes in speeds of vehicles. G levels are further reduced by rear safety bumpers, by

17 the laminate bodies, by the various interior crash pads, and/or by flexible seat belts, air bags or other interior safety devices. In addition, occupants sitting close to, or voluntarily leaning against, interior crash pads or being thrown into them by the drivers braking just before impacts 'will benefit from further reductions of G forces delivered to them. Thus the decelerations and accelerations experienced by vehicle occupants at the collision speeds used in the foregoing calculations and impact tests are generally reduced to levels which do not cause serious injury.

(4) Characteristics of preferred padding material As indicated above, the preferred kinds of padding used in the invention are shock-absorbing unicellular blends of thermoplastic resin, NBR and plasticizer sold under the trademark Ensolite. The discussion in this section of the specification is specifically directed to such preferred padding materials. The advantages of this kind of material over various other shock-absorbing materials which might be used include the following:

(a) The compression resistance of the material during the first S to or so of compression is generally low enough to permit it to conform closely to varied shapes of the human anatomy or other objects striking it or struck by it so that injury or damage during this portion of the stroke is avoided, and during the rest of the stroke nearly equal compression resistance is exerted over the entire contact area, reducing the chances of injury or damage.

(b) The material, with the possible exception of Ensolite Type LDAF the static compression resistance of which is 18-26 p.s.i., decelerates or accelerates human bodies in distances no greater than the stroke lengths of the bumpers or of the interior crash pads of the invention with compression resistances which in terms of pressure (lb. per square inch) are generally moderate enough to be harmless to the anatomy. This property means that pedestrians, cyclists, animals, and vehicle occupants can generally be stopped with impact-resisting pressures gentle enough to save them from death or serious injury.

(c) The material tends to compress slowly. Its compression resistance is greater against fast compression than against slow compression. This property of the material apparently arises from its visco-elastic properties and inertia and from its closed-cell structure with gas confined inside the cells. (The momentarily undissipated heat generated in a rapidly compressed confined gas raises its temperature and compression resistance at any given stage of compression above what they would be during slow compression.) Thus a piece of the material adjusts automatically so as to exert less force and give more moderate shocks to vehicles, people, and animals in lower-speed collisions, lateral collisions, back-to-front collisions, collision impacts involving more than one mass of shock-absorbing materials, and bumper impacts with relatively light-weight objects (light-weight relative to bumper-contact areas) such as the anatomies of people and animals. By contrast, a piece of shock-absorbing foam having relatively uniform compression resistance in both slow and fast compressions and designed to stop high-speed impacts with forces near to survival limits of people and vehicles during head-on collisions would exert greater force than the preferred material to stop impacts during low-speed collisions, lateral collisions, back-to-front collisions, collision impacts involving other masses of shock-absorbing materials, and bumper impacts with light weight objects, giving vehicles, and animals shocks closer to the intensity of those incurred in high-speed head-on vehicle collisions. If designed to utilize more of its thickness to stop low-speed impacts with more moderate forces, the latter type of foam would exert higher peak Gs in stopping the high-speed impacts.

(d) During impacts at moderate highway speeds the materials compression resistance stays roughly constant after a quick initial build-up, not rising sharply until after about 65% compression. This means that most impacts can be stopped smoothly, with relatively moderate impact-resisting forces relative to the weights involved (moderate G's) Stated another way, the material can absorb unusually large amounts of kinetic energy during impacts without exceeding G levels which can be tolerated by people and vehicles during the deceleration or acceleration times required. During slOW impacts the material actually offers more compression resistance in the early stages (say at 25% compression than at 50-60% compression) when the speed of impact slows down. However, metal bumpers, trees, human heads, and bones penetrate portions of the material to increasing depths and with increasing impact area as compression progresses, creating greater compression resistance in the later stages of such impacts as explained in (g) below. In such cases, higher compression resistance of the material early in the impact and extra resistance to narrow objects built up later in the impact would tend to equalize, again minimizing the Gs. If compression resistance is found to be excessive in the early stages of low-speed head-on collisions between vehicles, it could be reduced by sharper tapering of bumpers to reuce their areas involved in the initial stages of impact, or by using appropriate combinations of types of the material which have different levels of compression resistance.

(e) After approximately 60-70% compression, the material brings into play an increasingly strong reserve of compression resistance which increases smoothly to very high resistances in the ultimate stages of the most violent collisions when the closed cells and confined gas of the material are compressed severely, saving vehicles and people from the destruction of an abrupt final stop.

(f) The average static compression resistance of the material relative to its weight or volume is several times that of open-cell flexible foams such as polyurethane, and the average dynamic compression resistance compares even more favorably. Thus safety bumpers and crash pads made from the material in convenient dimensions and weights can handle higher-speed collisions than opencell flexible foam could handle.

(g) During crashes the materials tensile strength, ranging from to more than psi. for the various preferred types, combined with a related build-up of diagonal compression resistance from material being compressed beneath the stretched material around narrow areas of impact, causes narrow objects such as metal bumpers or trees to encounter more compression resistance per square inch of their surface areas than is encountered by a flat surface covering the entire area of a bumper made in accordance with the invention. The deeper the penetration, the stronger this extra resistance to narrow objects becomes. The tensile strength and diagonal compression resistance also spread out the impact forces from narrow objects before they reach the sheets of laminate placed behind the material.

(h) The material is slow to rebound after impact and generally delivers rebound energy of less than 25% of impact energy absorbed, thus reducing rebound shocks and reducing secondary collisions to vehicles, people, and animals, and reducing changes in vehicle velocities during collisions toward an optimum of half what they would be with full padding rebounds, thus helping to reduce all interior crash pad thickness requirements by up to 75%. It is believed that the slow rebound is due to the content of PVC, which is fully compatible with the NBR (nitrile rubber) and the plasticizer(s), and that this quality is not obtainable at low cost using flexible sponges made of fast-rebounding polymers not compatible with (and therefore not useable in admixture with) PVC or with other low-cost resins having equivalent properties.

(i) In off-center collisions, the materials tensile strength and related diagonal compression resistance give extra compression resistance at the inside edge of the area of impact, and its flexibility allows the floating laminate sheet to tip toward the side of the impact, helping in both ways to convert head-on collisions into sliding collisions which reduce impact forces as described earlier.

(j) The compression resistance of the material increases in cold weather. This property could be considered an advantage because it automatically increases shock-absorbing capacity for the ice-covered roads and poorer braking conditions encountered in winter. Laboratory measurements based on static compression resistance indicate that cold weather compression resistance of the material reaches several times that of warm weather, which is an excessive increase. However, dynamic compression resistance probably increases less sharply in cold weather than does static compression resistance, possibly partly because the nitrogen in the closed cells is contracted, making its contribution relatively less important. Also variations in the material formulation, or even substitution of a different closed cell material (in alternate plies, for example), can moderate this property if deemed necessary.

(k) The material is made in various degrees of impact resistance, and different types have different compression resistance characteristics. This makes for easy tailoring of bumpers and interior crash pads by using combinations of different types to minimize vehicle damage and minimize injuries to pedestrians, cyclists, animals, and vehicle occupants in various kinds of collisions with various kinds of vehicles.

(1) The material recovers most of its shape after impact, and can be further restored when necessary by heating to temperatures in the magnitude of 150 degrees F. The material does not tear apart easily, and can be cheaply coated with PVC or other protective surfaces for high weather resistance, abrasion resistance, toughness, and siipperiness. Its closed-cell structure does not absorb water so that rain and dampness present no problem. The material can withstand flexing without damage at extremely low temperatures and is fire-retardant. It has low gas permeability and does not lose its internal gas pressure when heated, as when left in the hot sun. Thus the safety bumper itself is not likely to be damaged by accidents or severe weather conditions. Most other materials lack one or more of the foregoing properties.

from many angles, whereas metal shock absorbers are limited in this respect. To handle such collisions, many shock absorbers with expensive, heavy coordinating mechanisms becomes necessary.

(p) Chiefly as a result of properties described above, the material has demonstrated its ability to stop various types of impacts with significantly less peak Gs than is the case with other kinds of shock-absorbent foam rubber and without any serious rebound shock or secondary shock.

There have been reported cases of live people falling from upper storey windows and from aircraft and landing flat in fiower beds or other soft earth uninjured, even though Gs in the magnitudes of 200 to 500 probably were exerted. The extensive data collected and analyzed by NASA includes cases where humans have survived impact Gs beyond 200. In addition to G5, time duration of G5 and direction of force, the contour, deformation, and rebound characteristics of the impact-absorbing device or material involved have been found to be important determinants of the degree of injury sustained. Somewhat analogously, raw eggs dropped from buildings and hitting one-inch sheets of the preferred padding material at mph have survived with shells and yokes unbroken, even though they must have endured more than one six hundred Gs of force. Plastic replicas of human heads have been catapulted against heavy steel plates covered with 4 inch layers of the preferred material at 70 mph. (enduring at least 660 Gs of stopping force) without damage. The preferred material is the oflicial boxing-ring platform material in the State of New York, and no serious head injuries by contact with platforms have been reported since it was adopted. The material is used as the underlay in artificial turf used in football fields and is Widely used for gym mats, athletic equipment, crash helmets, etc. Although the foregoing facts have been generally known, it has never occurred to those skilled in the art to use the preferred material in the ways contemplated by the present invention and thereby greatly reduce damage, injuries and deaths from motor vehicle collisions.

The properties of the material in comparison with the properties of alternatives which might be considered are set forth in the following table:

Flexible open-cell Metal liquid shock sponges Rigid foams absorbers (8) Initial soft compression resistance Yes No (b) Moderate impact pressures Yes Possible. s

(c) Adjusts for imt or slow impacts (d) Constant resistance through most of impact (e) smoothly rising resistance at end of impact compression (I) Adequate for higher speed impacts gg Extra resistance pressure to narrow objects."

h Blow rebound (or none) 5;; Extra impact resistance and sliding in ofl-ceuter collisions- Compression resistance greater in winter (k) Various types available (l) Recovers shape and resists damage m) Minimizes total vehicle weight.

ay 0.. Y

11 Low cost N0. No 0 Handles oft-center and angular collisions Yes No. p Outstanding shock absorption already demonstrated Yes No In some cases. At low speeds.

(m) Because of its light weight relative to its dynamic impact resistance, its extra impact resistance against narrow objects, its damage resistance, and its flexibility, the material in safety bumpers requires no heavy or complicated frontal barriers, supports, or back-up mechanisms. Thus it helps to reduce braking distances, frequency of collisions, collision speeds, forces of impact, gasoline consumption, and vehicle production costs.

(n) Relative to its dynamic compression resistance the material is low in cost. For example, it costs only a fraction as much as open-cell flexible polyurethane foam or metal shock absorbers for equivalent impact resistance and stroke length.

(0) The material as used in the safety system of the in- (5 Characteristics of preferred laminate The preferred laminate is a rigid but bendable, shockabsorbing, impact-resistant, thermoformable laminate having a rigid unicellular ABS core and having integrally bonded to this core on each side thereof one or more substrate layers of solid ABS thermoplastic material and one or more skin layers of thermoplastic material bonded to the substrate layers such as are described in detail in the several patents and publications cited in the above definition of laminate. It is superior to ABS sheets laminated to polyurethane cores in terms of impact strength, recovery, repairability, ease of fabrication, etc. The advantages of the preferred laminate over other mavention is effective in off-center collisions and collisions terials which might be considered for use in the safety 21 bumpers or vehicle bodies or fenders include the following:

(a) Greater rigidity relative to weight than steel, polyester-fiberglass, alumina, etc.-crucial for the safety bumper described herein. High quality plywood has up to 25% greater stiffness-to-weight than the preferred laminate, but lacks impact resistance and shatters, splits, and splinters under severe impact.

(b) Great flexural strength requiring less reinforcement than other structural materialscrucial for the safety bumpers, bodies and fenders.

(c) Greater impact resistance relative to weight than any of the aforementioned materials, as a result of the ABS resins contained in the substrate layers and core of the preferred laminate plus the nitrogen-filled closed cell structure of the core, in which each cell acts as an energyabsobing center for the impact loading. Fender and body damage on big Diamond Reo (trademark), White (trademark), and International Harvester (trademark) trucks operating commercially with fenders and cabs made from the preferred laminate has been negligible. Cars with bodies made from it have been driven at 30 m.p.h. through brick walls without body damage. A strong man with a sledge hammer has difficulty making a dent in a fender made from this laminate. A logging truck whose metal cab was crushed when it rolled over suffered only minor damage to the hood and fenders made of the laminate, saving the driver from injury. This high resistance of the preferred laminate to both lateral and longitudinal impacts is important for the safety bumpers, for the body connected directly to the safety bumpers, for reduction of dents and other damage to fenders and body, and for protection of vehicle occupants.

(d) Ability to bend and compress slightly and ultimately dent and crush under extreme impact both laterally and longitudinally, thus reducing forces of impact delivered to vehicle frames, engines, and other components, reducing stresses on the connections between frame, body, engine, etc., and protecting vehicle occupants from excessive shocks and from collapse of vehicle bodies during collisions or capsizing accidents.

(e) Slow recovery from bending and compression even within elastic limits, which reduces rebound shocks, secondary collisions, and velocity changes.

(f) Does not shatter or splinter even during extremely severe crashes. Makes no flying fragments, jagged edges, or splinters as do the aforementioned materials.

(g) Dents in the preferred laminate are easily repaired by aiming a cheap electric heat gun at the dent, which simply pops back into place with assistance from reexpansion of the gas in each of the closed cells upon heating. Often dents repair themselves after a few hours without any work being done on them. Blemishes are washed 01f with soap and water. Holes from extremely violent impacts can be easily patched with epoxy compounds.

The light weight of bodies, fenders, and bumper components made of the preferred laminate reduces motor vehicle weights, reducing braking distances, frequency of collisions, average collision speeds, and collision impact forces, as well as gasoline consumption and automotive production costs.

(i) Like the preferred padding material, the preferred laminate becomes stronger in cold weather, automatically tending to compensate for slippery roads and poor braking conditions, and substantially maintains its desirable characteristics over a wide range of temperatures beyond those commonly encountered by motor vehicles.

(j) The preferred laminate is readily formable by conventional thermoforming operation such as vacuum drawing or any other thermal forming techniques such as those described in the aforementioned brochure entitled Royalex ABS: properties and uses and in the book "Plastic Sheet Forming by Butzko, published 1958 by Reinhold. This formability depends on the unicellular construction of the core which prevents collapse of the individual closed cells during stretching and forming at elevated temperatures as well as upon the fact that its cover layers are thermoplastic and heat-formable. Since both the core 23 and the substrate layers 24 (which are disposed on each side of the core and constitute important elements of the cover layers) are both made from ABS they have identical or closely similar thermoplastic characteristics which cause them to exhibit like heat-drawing and -forming behavior; the outer skin layers 25 are thermoplastic also but are usually so thin that even when they are not made of ABS they follow the movement of the core and substrate layers during forming. Thus because the core is made of ABS and has a closed cell structure it behaves as if it were a homogeneous or non-cellular material in the drawing step and stretches and thins out in unison with the cover layers.

(6) Preferred laminate and padding materials Both the preferred laminate, e.g. "Royalex sheet and the preferred padding material, eg shock-absorbing forms of Ensolite are lightweight and easy to cut, laminate, drill, thermoform, attach, cement, coat, etc, and therefore lend themselves to low-cost commercial production of vehicles incorporating the safety system described herein. Initial investments for tooling, molds, and other equipment are very small compared with the investments to produce components out of metal, polyester-fiberglass, or other available material.

GENERAL It will be understood that the foregoing disclosure is illustrative and not limiting. For example, the front safety bumpers could have a padding thickness outside the preferred limits of from 12 to 18 inches. Thus for lighter vehicles and for handling lower speed collisions, the thickness might be as low as 9 inches. Conversely, for heavy vehicles such as trucks or for extremely high collision speeds, the thickness might be as great as 24 inches. Similarly the padding thickness in the rear bumper might be as low as 4 inches and as high as 12 inches.

The ends of the motor vehicle need not be perfectly fiat but can be moderately rounded or beveled with certain attendant advantages and disadvantages.

It will be seen that the inner laminate panels of the safety bumpers are reinforced at least by the side portions of the body shell and that the panels are typically additionally reinforced along their upper portions by the upper portions of the body shell. Thus, typically the side and upper portions of the body shell directly abut the side and upper portions of the inner laminate panels. In addition, the lower portions of these panels are reinforced by the transverse chassis members 7 against which they usually directly abut. The result is that the body shell, and preferably the chassis as well, act in concert with one or both of the safety bumpers in absorbing the energy of collisions; this cooperative effect is achieved to the best advantage when both these panels and the body shell are made from the laminate.

Since the rigid inner laminate sheets 4 and 5 of the safety bumpers are themselves fixedly mounted (in any suitable way as by mechanical attaching means or by solvent welding where laminate is joined to laminate) on the truncated ends of the body and chassis, the bumpers become in effect parts of the body and chassis. As a consequence, the safety bumper is able to directly and simultaneously decelerate or accelerate both the body and the chassis, and heavy internal components of the vehicle as well where longitudinal bracing, such as braces 21, is provided. The use of these damage-resistant, shock-absorbing, slowly recovering components together in the manner described also enables the interior crash pads to operate with maximum effectiveness in reducing injuries.

While no provision for cooling the engine of the vehicle is shown in the drawings or described in the foregoing, those skilled in the art can readily provide suitable means for accomplishing such cooling. Thus any suitable means can be used for drawing cooling air into and around the engine where it is air-cooled or through the radiator of a liquid-cooled engine. Air intakes or scoops can be provided in the hood or in the sides of the body shell or even at the bottom of the vehicle.

The safety system of the invention can be used, if desired, in combination with other known safety-enhancing and damage-reducing system or devices such as safety belts, inflatable air bags in the passenger compartment, metal hydraulic shock absorbers (which could if desired be positioned between the floating laminate sheet of a safety bumper of the invention and the chassis, engine block or other heavy internal components of the vehicle), clear plastic Windshields and windows, etc.

The automotive safety system of the invention can prevent damage and injuries at relatively high collision speeds without being destroyed or severely damaged itself and thus without becoming a significant part of vehicle repairs. By contrast, other auto-motive safety systems reported up to now themselves often become damaged at speeds exceeding to 30 mph, adding greatly to repair bills.

While the aforementioned shock-absorbing unicellular blends of resin, nitrile rubber and plasticizer(s), such as those known as Ensolite," are the materials of first choice for the padding used in the safety bumpers and interior crash pads of the invention, other cellular, shockabsorbing polymeric materials having similar properties to an acceptable degree but not unduly sacrificing other desirable qualities and not involving excessive costs, can be used in lieu thereof.

While it is preferred that the fixed and floating sheets 4, 5, 13 and 15 of the safety bumpers and the body 1 of the vehicle both be made from the laminate described above, the material from which the sheets or the body or both are made can with some disadvantages be replaced with other sheet materials having stiffness, flexibility, compressibility, compression resistance, tensile strength, density, impact resistance, slow rebound, ability to recover shape after impacts, resistance to delamination, ease of processing and fabricating, and ease of repairing to degrees which are acceptable if the cost of such materials is low enough. A good example of such a possible substitute material is a sandwich sheet construction consisting of solid ABS sheets bonded to a rigid closed cell polyurethane foam core, described in Chemical & Engineering News, Oct. 13, 1969, pages 50-51. A possibility for the bumpers only might be high grade plywood but it is subject to certain serious shortcomings mentioned above.

Those skilled in the art will, of course, appreciate that care must be exercised in the selection of particular materials used in the safety bumpers, body and interior crash pads. For example the type of shock-absorbing material known as Ensolite" Type LDAF has relatively high compression resistance and therefore should be used with caution in the interior crash pads and in the outer portions of bumpers which are likely to strike people or animals. The teachings of the foregoing specification will sufiiciently apprise those skilled in the art how to design a motor vehicle embodying the principles of the present invention.

Those skilled in the art will also appreciate that the different conditions to which the padding used in the safety bumpers of the invention and the padding of the interior crash pads are exposed often dictate somewhat different physical properties for these materials. Thus, the dynamic compression resistance required for the padding used in the interior crash pads is normally somewhat less than is required for the padding used in the safety bumpers. Also the tensile strength of the padding used in the interior crash pads is not necessarily as great as that which is desirable in the bumper padding to resist tearing and to help resist impacts from collisions with narrow objects such as trees and metal bumpers. While the tensile strength of the padding in the crash pads might be as low as 15 pounds per square inch, for the bumpers it is preferred, but not essential, that it be at least 50 pounds per square inch. Again, since the bumper padding is more likely to be exposed to the elements than are the interior crash pads, it is desirable that the bumper padding have a water absorption value not over 1 pound per square foot of cut surface; such a requirement is not essential for the padding from which the interior crash pads are made.

The expressions relatively thin used in certain of the claims to denote elements 4, 5, 13 and 15 of the safety bumpers and relatively thick used in those claims in describing elements 11, 12, 14 and 16 of the bumpers refer to the longitudinal thicknesses of the elements of each group in comparison with the longitudinal thickncsses of the elements of the other group. In practice the thicknesses of elements 11, 12, 14 and 16 commonly range from 4 to 20 times the thicknesses of elements 4, 5, 13 and 15.

The term stifi used in certain of the claims in describing the material from which elements 4, 5, 13 and 15 are formed is used in its commonly accepted meaning to indicate that such material is rather rigid and inflexible although it generally is somewhat bendable under high loading. Preferably such material has a stiffness in flexure (EN/l2) relative to weight per unit of area at least equal to 50% of that shown for laminates in FIG. 9.

The term boardy has its usual and ordinary meaning namely not pliable, hard, stiff.

From the foregoing it will be seen that the present invention provides a simple, relatively inexpensive, foolproof but highly effective system for greatly reducing injuries and damage from motor vehicle collisions at speeds higher than those at which previously used or proposed techniques had any effectiveness. The present invention is unique in that it depends for its effectiveness mainly upon types of polymeric materials which have been readily available for a number of years but were never used together in the manner of the invention. In the practice of the invention these well-known materials are utilized in particular novel ways in the construction of the vehicle so that they cooperate to achieve the aforementioned reduction in injuries and damage. The invention involves no heavy, expensive, damage-prone, or hard-to-repair mechanisms. The polymeric components of the safety system of the invention are unusually hard to damage and easy to repair.

While the invention in its preferred form uses the novel safety bumpers in combination with a motor vehicle body made of the laminate and the interior crash pads formed of the padding as described in the foregoing and portrayed in the drawings, in its broader aspects it is not limited thereto but is to be taken as limited only as set forth in the claims appended hereto.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

1. In a motor vehicle, a body shell including side and top portions of boardy sheet thermoplastic material comprising a laminate of solid plastic cover layers integrally united to an inner rigid cellullar plastic core, said laminate having a stiffness in flexure (ET /12) relative to weight per unit of area at least as great as that shown for laminates in FIG. 9 of the accompanying drawings and an impact resistance such that it shows no break when a 2 lb. steel ball is dropped on it from a height of 9 feet at temperatures ranging from 40 F. to F.; a chassis for supporting said body shell, said chassis including a transverse support member; and a bumper assembly comprising a substantially vertically arranged layer of polymeric sheet material and a mass of cellular polymeric material disposed on a face of said layer, said mass of cellular polymeric material comprising a major portion of the volume of said bumper assembly, said bumper assembly including side, top and bottom portions, at least the top portion of 25 said body shell and said transverse support member being in reinforcing contact with the top and bottom portions, respectively, of said bumper assembly so as to act in concert therewith in absorbing the energy of collisions.

2. In a motor vehicle, a body shell including side and top portions of boardy sheet thermoplastic material comprising a laminate of solid plastic cover layers integrally united to an inner rigid cellular plastic core, said laminate having a stiffness in flexure (ET /12) relative to weight per unit of area at least as great as that shown for laminates in FIG. 9 of the accompanying drawings and an impact resistance such that it shows no break when a 2 lb. steel ball is dropped on it from a height of 9 feet at temperatures ranging from 40 F. to 175 F.; a chassis for supporting said body shell, said chassis including at least a front transverse support member; and at least a front bumper assembly comprising the following elements:

(1) A substantially vertically arranged sheet of boardy thermoplastic material disposed fixedly over the front end of said body shell, said sheet comprising a laminate responding to the foregoing description of the laminate from which said body shel lis formed,

(2) A relatively thick mass of unicellular shock-absorbing polymeric material disposed on the outer face of element (1) and having the following physical properties:

Density-not over 35 lbs. per cu. ft.

25 compression resistance (dynamic at approximately 25 miles per hour, for 12-inch thickness)-at least 15 lbs. per sq. in.

Tensile strength-at least 15 lbs. per sq. in.

Water absorption (cut surface)not over 1 lb. per

sq. ft.

Rebound energy delivered-not more than 35% of impact energy said mass of unicellular material comprising a major portion of the volume of said bumper assembly, said bumper assembly including side, top and bottom portions, at least the side portions of said body shell engaging and reinforcing the inner face of element (1) at the side portions thereof, and the transverse support member engaging and reinforcing the inner face of element (1) at the bottom portion thereof such that the body shell, the chassis and the bumper assembly act in concert with one another in absorbing the energy of collisions.

3. In a motor vehicle, a body shell including side and top portions of boardy sheet thermoplastic material comprising a laminate of solid plastic cover layers integrally united to an inner rigid cellular plastic core, said laminate having a stiffness in fiexure (ET 12) relative to weight per unit of area at least as great as that shown for laminates in FIG. 9 of the accompanying drawings and an impact resistance such that it shows no break when a 2 1b. steel ball is dropped on it from a height of 9 feet at temperatures ranging from 40 F. to 175 F.; a chassis for supporting said body shell, said chassis including front and rear transverse support members; and front and rear bumper assemblies, each of said assemblies comprising the following elements:

(1) A sheet of boardy thermoplastic material disposed fixedly over an end of said body shell, said sheet comprising a laminate responding to the foregoing description of the laminate from which said body shell is formed,

( 2) A relatively thick mass of unicellular shock-absorbing polymeric material disposed on the outer face of element (1) and having the following physical properties:

Densitynot over 35 lbs. per cu. ft.

25% compression resistance (dynamic at approximately 25 miles per hour, for l2-inch thickness)at least 15 lbs. per sq. in.

Tensile strength-at least 15 lbs. per sq. in.

26 Water absorption (cut surface)--not over 2 lb. per

sq. ft. Rebound energy delivered-not more than 35% of impact energy.

(3) A second relatively thin sheet of boardy thermoplastic material disposed on the outer face of element (2), said second sheet comprising a laminate ersponding to the description of the laminate in connection with element (1), and

(4) A second relatively thick mass of unicellular shockabsorbing material disposed on the outer face of element (3), said material having the properties set forth in connection with element (2) said bumper assemblies each including side, top and bottom portions, the side portions of said body shell engaging and reinforcing the inner face of element (1) of each bumper assembly at the respective side portions thereof, the top portion of said body shell reinforcing the inner face of element (1) of each bumper assembly at the top portions thereof, the front transverse support member reinforcing the inner face of element (1) of the front bumper assembly at the lower portion thereof, and the rear transverse support member reinforcing the inner face of element (1) of the rear bumper assembly at the lower portion thereof such that the body shell, the chassis and one, the other, or both of the bumper assemblies act in concert with one another in absorbing the energy of collisions.

4. A motor vehicle having its body and fenders formed from boardy sheet thermoplastic material comprising a laminate of solid plastic cover layers integrally united to an inner rigid cellular plastic core, said laminate having a stiffness in flexure (ET 12) relative to weight per unit of area at least equivalent to that shown for laminates in FIG. 9 of the accompanying drawings and an impact resistance such that it shows no break when a 2 lb. steel ball is dropped on it from a height of 9 feet at temperatures ranging from 40 F. to F., and having substantially flattened front and rear ends on which are fixedly mounted bumpers extending over substantially the entire areas of said front and rear ends, respectively, each of said bumpers comprising the following elements:

(1) A relatively thin sheet of still, somewhat flexible, highly impact-resistant material disposed fixedly over the front or rear end of the motor vehicle, said material having a stitfness in fiexure' (ET /l2) relative to weight per unit of area at least as great as that shown for laminates in FIG. 9 of the accompanying drawrugs,

( 2) A relatively thick mass of cellular shock-absorbing plplymeric material disposed on the outer face of said 5 eet,

(3) A second relative thin sheet of stiff, somewhat flexible, highly impact-resistant material responding to the description of material in element (1), disposed on the outer face of element (2), and

(4) A second relatively thick mass of cellular shockabsorbing polymeric material disposed on the outer face of element (3).

5. A motor vehicle having its body and fenders formed from rigid sheet thermoplastic material comprising a laminate of solid plastic cover layers integrally united to an inner rigid cellular plastic core, said laminate having a stiffness in flexure (ET/l2) relative to weight per unit of area at least equivalent to that shown for laminates in FIG. 9 of the accompanying drawings and an impact resistance such that it shows no break when a 2 lb. steel ball is dropped on it from a height of 9 feet at temperatures ranging from 40 F. to 175 F., and having substantially flattened front and rear ends on which are fixedly mounted bumpers contacting said body and extending over substantially the entire areas of said front and rear ends, respectively, each of said bumpers comprising the following elements:

(I) A substantially vertically arranged relatively thin sheet of still, somewhat flexible, highly impact-resistant material disposed fixedly over the front or rear end of the motor vehicle, said material having a stitfness in fiexure (ET/l2) relative to weight per unit of area at least as great as that shown for laminates in FIG. 9 of the accompanying drawings, and

(2) A relatively thick mass of cellular shock-absorbing polymeric material disposed on the outer face of said sheet.

6. A motor vehicle comprising a chassis frame, a body shell over said frame having a side portion on each side of said frame and defining the outer side of said vehicle, a transversely extending and substantially vertically arranged stilf bumper plate extending along one end of said frame and reinforced by said frame, said body shell having a foremost end portion extending in a direction parallel to the travel direction and terminating in a front across which said bumper plate extends, said bumper plate covering a major portion of said front and a mass of cellular polymeric material covering said bumper plate and being of generally uniform thickness and extending outwardly from said plate, at least the side portions of said body shell being in reinforcing rigid contact with said bumper plate so as to act in concert therewith in absorbing the energy of a collision.

7. In a motor vehicle, a body shell including side and top portions of boardy sheet thermoplastic material comprising a laminate of solid plastic cover layers integrally united to an inner rigid cellular plastic core, said laminate having a stiffness in fiexure (ET/ 12) relative to weight per unit of area at least as great as that shown for laminates in FIG. 9 of the accompanying drawings and an impact resistance such that it shows no break when a 2 lb. steel ball is dropped on it from a height of 9 feet at temperatures ranging from 40 to 175 F.; and, at least a front bumper assembly comprising the following elements:

(1) A substantially vertically arranged sheet of boardy thermoplastic material disposed fixedly over the front end of said body shell, said sheet comprising a laminate responding to the foregoing description of the laminate from which said body shell is formed,

(2) A relatively thick mass of unicellular shock-absorbing polymeric material disposed on the outer face of element (1) and having the following physical properties:

Density-not over 35 lbs. per cu. ft.

25% compression resistance (dynamic at approximately 25 miles per hour, for l2-inch thickness)at least 15 lbs. per sq. in.

Tensile strengthat least 15 lbs. per sq. in.

Water absorption (cut surface)-not over 1 lb. per

sq. ft.

Rebound energy delivered-not more than 35% of impact energy.

said mass of unicellular material comprising a major portion of the volume of said bumper assembly, said bumper assembly including side, top and bottom portions, at least the side portions of said body shell being in reinforcing contact with the inner face of element (1) at the respective side portion thereof such that the body shell and the bumper assembly act in concert with one another in absorbing the energy of collisions.

8. In a motor vehicle as described in claim 7, said top portion of said body shell engaging and reinforcing the inner face of element (1) at the top portion thereof.

9. In a motor vehicle as described in claim 8, a chassis for supporting said body shell, said chassis including a transverse support member, said engaging and reinforcing the inner face of element (1) at the bottom portion thereof.

10. In a motor vehicle as described in claim 9, said bumper assembly being located at the front end of said 28 body shell, and a second bumper assembly located at the rear end of said body shell, said second bumper assembly comprising the following elements:

(3) A sheet of boardy thermoplastic material disposed fixedly over the rear end of said body shell, said sheet comprising a laminate responding to the description of the laminate from which said body shell is formed,

(4) A relatively thick mass of unicellular shock-absorbing polymeric material disposed on the outer face of element {3) and having the following physical properties:

Density-not over 35 lbs. per cu. ft.

25% compression resistance (dynamic at approximately 25 miles per hour for 12-inch thickness)at least 15 lbs. per sq. in.

Tensile strengthat least 15 lbs. per sq. in.

Water absorption (cut surface)not over 1 lb. per

sq. ft.

Rebound energy delivered-not more than 35% of impact energy.

said mass of unicellular material comprising a major portion of the volume of said rear bumper assembly, said rear bumper assembly including side, top and bottom portions and having a maximum cross-sectional area equal to at least 50% of the maximum projected cross-sectional area of said body shell, the side and top portions of said body shell reinforcing the inner face of element (3) at the respective side and top portions thereof.

11. In a motor vehicle as described in claim 10, said chassis including a rear transverse support member, said member reinforcing the inner face of element (3) at the bottom portion thereof.

12. A motor vehicle having its body and fenders formed from boardy sheet thermoplastic material comprising a laminate of solid plastic cover layers integrally united to an inner rigid cellular plastic core, said laminate having a stiffness in flexure (ET /l2) relative to weight per unit of area at least equivalent to that shown for laminates in FIG. 9 of the accompanying drawings and an impact resistance such that it shows no break when a 2 lb. steel ball is dropped on it from a height of 9 feet at temperatures ranging from 40 F. to F., and having substantially flattened front and rear ends on which are fixedly mounted bumpers engaged against said body and extending over substantially the entire areas of said front and rear ends, respectively, each of said bumpers comprising the following elements:

(1) A sheet of boardy thermoplastic material disposed fixedly over the front or rear end of the motor vehicle, said sheet comprising a laminate responding to the foregoing description of the laminate from which the body and fenders are formed,

(2) A relatively thick mass of unicellular shock-absorbing polymeric material disposed on the outer face of element (1) and having the following physical properties:

Density-not over 35 lbs. per cu. ft.

25% compression resistance (dynamic at approximately 25 miles per hour, for 12-inch thickness)at least 15 lbs. per sq. in.

Tensile strength-at least 15 lbs. per sq. in.

Water absorption (cut surface)not over 1 lb. per

sq. ft.

Rebound energy delivered-not more than 35% of impact energy (3) A second sheet of boardy thermoplastic material disposed on the outer face of element (2), said second sheet comprising a laminate responding to the foregoing description of the laminate from which the body and fenders are formed, and

(4) A second relatively thick mass of unicellular shockabsorbing material disposed on the outer face of element (3), said material having the properties set forth in connection with element (2).

13. A motor vehicle as set forth in claim 12 wherein said unicellular material is a blown compatible blend of thermoplastic resin, NBR and plasticizer in proportions of from to 70% of said resin, from 16% to 80% of said NBR and from 8% to 60% of said plasticizer, said percentages being by weight based on the sum of said constituents and totalling 100%.

14. A motor vehicle as set forth in claim 12 wherein laterally spaced fixed metal braces extending generally longitudinally are provided between element (1) of one of said bumpers and the engine block or other heavy internal component of the vehicle.

15. A motor vehicle as set forth in claim 12 wherein the maximum transverse area of each of said bumpers is equal to at least 50% of the maximum projected transverse cross-sectional area of the vehicle including windshield and roof.

16. A motor vehicle comprising a chassis frame, an engine mounted on said frame, a body shell over said frame having a side portion on each side of said frame defining the sides of said vehicle, a transversely extending and substantially vertically arranged stiff bumper plate arranged transversely along one end of said frame and reinforced by said frame, said body shell having a foremost end portion covering said engine and both sides and a top extending in a direction parallel to the travel direction and having a front end, said bumper plate covering substantially the major portion of said front end, a mass of cellular, polymeric material covering said bumper plate and extending outwardly from said plate in the direction of travel and a rigid bracing extending forwardly from said engine to said bumper and in reinforcing contact with said bumper.

17. A motor vehicle according to claim 16 wherein at least a portion of said body shell is also in reinforcing contact with said bumper plate so as to act in concert therewith in absorbing the energy of a collision.

18. In a motor vehicle as described in claim 16, a chassis for supporting said body shell, said chassis including a transverse support member, said member reinforcing the bottom portion of said bumper assembly.

19. In a motor vehicle as described in claim 16, said sidewall and top portions of said body shell being in abutment with and fixedly secured to a face of said layer of polymeric sheet material of said bumper assembly.

20. In a motor vehicle as described in claim 16, said bumper assembly being located at the front end of said body shell, and a second bumper assembly located at the the rear end of said body shell, said second bumper assembly comprising a layer of polymeric sheet material and a mass of cellular polymeric material, said second bumper assembly including side, top and bottom portions, at least the side portions of said body shell reinforcing the side portions of said second bumper assembly so as to act in concert therewith in absorbing the energy of collisions.

21. In a motor vehicle as described in claim 20, a chassis for supporting said body shell, said chassis including front and rear transverse support members, said top portion of said body shell reinforcing the top portion of each of said bumper assemblies, said front transverse support member reinforcing the bottom portion of said front bumper assembly, said rear transverse support member reinforcing the bottom portion of said rear bumper assembly.

22. In a motor vehicle, a body shell including side and top portions of rigid sheet thermoplastic material comprising a laminate of solid plastic cover layers integrally united to an inner rigid cellular plastic core, said laminate having a stiffness in fiexure (ET 12) relative to Weight per unit of area at least as great as that shown for laminates in FIG. 9 of the accompanying drawings and an impact resistance such that it shows no break when a 2 lb. steel ball is dropped on it from a height of 9 feet at temperatures ranging from 40 F. to 175 F.; and a bumper assembly comprising a substantially fiat and rigid generally vertically disposed layer of polymeric sheet material extending across one end of said vehicle and a mass of cellular polymeric material disposed on the exterior face comprising a major portion of the volume of said bumper assembly, at least the side portions of said body shell defining the sides of said vehicle and being in reinforcing contact with the side portions of said bumper assembly so as to act in concert therewith in absorbing the energy of collisions.

23. In a motor vehicle as described in claim 22, said top portion of said body shell reinforcing said top portion of said bumper assembly.

24. In a motor vehicle as described in claim 23, a chassis for supporting said body shell, said chassis including a transverse support member, said member reinforcing the bottom portion of said bumper assembly.

25. In a motor vehicle as described in claim 22, said bumper assembly being located at the' front end of said body shell, and a second bumper assembly located at the rear end of said body shell, said second bumper assembly comprising a layer of polymeric sheet material and a mass of cellular polymeric material disposed on a face of said layer, said mass of cellular polymeric material comprising a major portion of the volume of said second bumper assembly, said second bumper assembly including side, top and bottom portions and having a maximum cross-sectional area equal to at least 50% of the maximum projected cross-sectional area of said body shell, at least the side portion of said body shell reinforcing the side portions of said second bumper assembly so as to act in concert therewith in absorbing the energy of collisions.

26. In a motor vehicle as described in claim 25, a chassis for supporting said body shell, said chassis including front and rear transverse support members, said top portion of said body shell reinforcing the top portion of each of said bumper assemblies, said front transverse support member reinforcing the bottom portion of said front bumper assembly, said rear transverse support member reinforcing the bottom portion of said rear bumper assembly.

References Cited UNITED STATES PATENTS 2,916,324 12/1959 Graham 296-28 R 3,493,257 2/ 1970 Fitzgerald et al 293-71 R 2,074,469 3/1937 Haynes 293-63 X 2,962,107 11/1960 Mihal et a1 293-63 X 3,583,756 6/1971 Wilfert 296-31 P 1,789,039 1/ 1931 Gordon 293-71 R 2,829,915 4/1958 Claveau 293-71 R 3,339,907 9/1967 Parke! 267- 2,757,147 7/1956 Pooley 260-25 R 3,463,687 8/ 1969 Folsom et a1. 156-79 BENJAMIN HERSH, Primary Examiner L. I. PAPERNER, Assistant Examiner US. Cl. X.R. 

